Vaccine solutions will be applied to the upper deltoid area under a standard Tegaderm dressing. Key primary endpoints include: safety as measured primarily by clinical findings (VS, cutaneous exams, and systemic reactions), and immune responses as measured by serological responses to L. monocytogenes, influenza A nucleoprotein, CT, and IFN gamma ELISPOT responses to listeriolysin and nucleoprotein peptides. Local skin immune responses will be evaluated by skin biopsy in subjects who agree to that (optional). The study will begin with 2 "roll-in" subjects receiving both L. monocytogenes and CT.